A bicycle has pedal rods of length `16 cm` connected to sprocketed disc of radius `10 cm`. The bicycle wheels are `70 cm` in diameter and the chain runs over a gear of radius `4cm`. The speed of the cycle is constant and the cyclist applies `100 N` for, that is always perpendicular to the pedal rod, as shown in figure. Assume tension in the lower part of chain is negligible. The cyclist is peddling at a constant rate of two revolutions per second. Assume that the force applied by other foot is zero when one foot is exerting `100 N` force. Neglect friction within cycle parts and the rolling friction.

The speed of the bicycle is

Options

A. `6.4pims^(-1)`
B. `3.5pims^(-1)`
C. `2.8pims^(-1)`
D. `6.5pims^(-1)`

Answer

B

Explanation

`RN=rnimpliesn=(10cmxx2)/(4cm)=5cy//s`
so rear wheel rotates `5 "cycles"//s`
Hence `V=35/100xx2pixx5=3.5pims^(-1)`